【A journey of a thousand miles begins with a single step – Centrifugal Pumps】1.1 Understanding the concepts: Classification and naming of pumps

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This post was last edited by 3983596_FPPZ on 2018-11-12 at 12:52: file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif. In our work, we come across many different types of pumps, which have various names and a wide range of models – such as methanol pumps, multi-stage pumps, deep well pumps, positive displacement pumps, self-priming pumps, bottom-of-tower pumps, vacuum pumps, boiler feed water pumps, PTFE pumps, shielded pumps, and so on. It can be confusing, right? So how exactly should these pumps be classified and distinguished from one another? 1.1.2 Classification and naming of pumps: Where there are differences, there is classification. Pumps can generally be divided into three categories: ● Vane pumps: Pumps that use the rotation of vanes on a rotor to deliver work on liquids. Vane pumps are the most widely used; they feature a simple structure, high flow rates, and a wide operating range. However, they are usually capable of transporting only relatively pure liquids with low viscosity. ●Positive displacement pump: A pump that generates work on the liquid by creating changes in volume within the pump. Positive displacement pumps feature high efficiency, reliable operation, and high outlet pressure, making them suitable for applications requiring high pressure and low flow rates or dealing with viscous fluids. ●Other pumps: Pumps that do not fall into the above two categories, such as jet pumps. The following are some pump classifications found in course materials; you can refer to them. The many names given to pumps are simply due to their different classifications, just as a Chinese man is called a Chinese citizen by nationality, is the son of his parents and the husband of his wife; when driving he is a driver, and when at work he is an employee. It’s similar to how men are classified by gender. Pumps are generally classified based on their structure; some are also classified by function, installation location, material, overall design, the medium they transport, and their specific characteristics, among other things. Different ways of classification give rise to different names, and there are relationships of inclusion and overlap among them. For example, a single-stage, single-suction horizontal centrifugal pump is called a single-stage pump based on the number of impellers; if it is used for transporting methanol, it is referred to as a methanol pump; if its material is stainless steel, it is called a stainless-steel pump. If its drive mechanism is magnetic drive, it is also known as a magnetic pump; and when it is used in firefighting, it is called a fire pump. Boaters should not get confused by the various names of pumps. Furthermore, the petrochemical pump standard API610 provides detailed classification regulations based on the pump structure; pumps of common types such as OH1, OH2, BB1, BB2, BB3, etc., are covered therein – you can refer to the standard for details. Pump model naming also varies widely; there are generally no mandatory rules, but they usually have several characteristics. For example, 100-80-250 typically indicates a nominal inlet diameter of 100 mm (4 inches) for the pump, a nominal outlet diameter of 80 mm (3 inches), and a nominal impeller diameter of 250 mm (10 inches). In chemical pumps, this naming convention based on the inlet and outlet diameters as well as the impeller diameter is quite common ； There are also pump models designated by flow rate and head parameters; for example, the segmented DY multi-stage pump: 12.5-50x6 means a flow rate of 12.5 m3/h, a head per stage of 50 m, 6 stages in total, with an overall head of 50*6=300 m. The meanings of these models cannot be generalized; the actual meaning of a model should be based on the information provided by the pump manufacturer. Nominal – it can generally be classified within a relatively standardized sequence of values, though the actual values may vary slightly. The centrifugal pump mentioned in the title, due to the customary terminology used in the industry, actually refers to the vane pumps listed in the table above. Classified by the number of impellers: single-stage, two-stage, and multi-stage pumps. Classified by the number of impeller inlets: single-suction pumps and double-suction pumps. Classified by the orientation of installation and use: horizontal pumps and vertical pumps (there are also those installed at an angle). Classified by the structural cross-section: radially split pumps, horizontally split pumps. Classified by pump structure: vortex pumps, tangential flow pumps, etc. Classified by the relative position between the pump and the liquid: submersible pumps and underwater pumps. Classified by the location of use: bottom-of-tower pumps, deep well pumps, etc. Classified by material: cast iron pumps, stainless steel pumps, PTFE pumps, etc. Classified by the medium handled: LPG pumps, methanol transfer pumps, heavy oil pumps, sewage pumps, etc. Classified by function: vacuum pumps, self-priming pumps, metering pumps, high-pressure injection pumps, unloading pumps, feed pumps, etc. Classified by……: …., …. ,….. ,……………………………………………………………………………………………………. Do you understand? There are indeed many different types of pumps, and they can be quite varied, but the fundamental principles remain the same. As long as one understands the characteristics of a pump and how to use it, it doesn’t matter what its name is; it’s just a name after all. I have more experience with centrifugal pumps; I rarely come into contact with other types of positive displacement pumps, as they are used less frequently. I hope my insights can serve as a starting point for others, encouraging more professional experts to share their knowledge and experiences, thereby enriching the forum. After-class question: To which category do slide pump belong? A. Vane pump, because it has slides that rotate to perform work ； B. Positive displacement pump, as it transports the medium through volume changes ； C. Cross-border pumps, both of which belong to ； D. Edge pumps; neither of these falls into that category, as they belong to other types of pumps.